(1) Field of the Invention
The present invention relates to the monitoring of harbor activity, and more particularly, to the detection of mines.
(2) Description of the Prior Art
There are nineteen harbors of prime interest in the United States, and many areas in other countries where maritime interests must be protected. These harbors vary in length, breadth, and depths from shallow to 300 feet. No system is yet known which can simply and reliably detect a wide variety of subsurface intruders such as swimmers and submarines, and mines launched by such intruders or by surface ships or aircraft. Although sweeps by ships are used for detecting mines and the like, these are very expensive, slow, intermittent, and do not provide reliable continuous monitoring and immediate surveillance of the entire channel.